Did the issues start after the dental? Rubbing face and nose sound more like an allergic reaction. Can she film her dog's seizure to show the specialists. That way they have something to go on rather than just a description. If her Vet only suggested MRI or put to sleep I would definitely consider a second opinion, and the MRI but perhaps it might be better done by a specialist.
Texas A&M Veterinary Medical Teaching Hospital according to google map directions Texas A& M is only 1 hour and 20 minutes drive from Elgin. Not that far for a thorough evaluation and diagnosis.